The present invention relates to a method for treating liver dysfunction.
In recent years, in Japan, reflecting the progressive increase in elderly population and the westernization of diet, the incidence of various diseases in the adult population has increased. One of these diseases is diabetes, which is a generic term for chronic high blood glucose and various complications (such as retinopathy, neuropathy, nephropathy and immune disorder) induced by capillary dysfunction accompanying the chronic high blood glucose. It is estimated that domestically about five million patients are suffering from these diabetes conditions. Diabetes is generally classified into insulin dependent diabetes mellitus (IDDM) and non insulin dependent diabetes mellitus (NIDDM). In Japan, it is reported that IDDM patients account for at most 5% of the diabetes patients, while NIDDM patients account for at least 95% of the diabetes patients. Particularly, NIDDM, which is related to habitat factors such as obesity, overfeeding, ataxia and senescence, is expected to increase in the future in Japan where the progressive increase in elderly population and the westernization of diet will further advance.
As the causes of IDDM, it is generally known that viral infection or defects of the autoimmunization mechanism cause inflammation of the Langerhaus islet of the pancreas, resulting in the destruction of beta-cells as the insulin-producing cells, whereby insulin will not be secreted. This develops IDDM. Accordingly, treatment is made by administration of insulin.
Further, as the causes of NIDDM, it is believed that although insulin is secreted, the action of the insulin on the cells is inadequate, whereby the cells can not sufficiently take glucose in the blood, and a hyperglycemia state is thereby continued. Accordingly, for the treatment, insulin is not necessarily required, and dietary treatment and excercise treatment are mainly used.
If the hyperglycemia state is continued by diabetes, systemic capillaries will fall into disorder and arteriosclerosis will advance, thereby causing obstruction of blood vessels in the heart or brain and gangrene of the legs. Further, if the blood glucose level is high, glucose in the blood is likely to bond to proteins in hemoglobin or tissues, whereby the functions thereof will be inhibited. As the results, complications such as retinopathy, nephropathy, neurosis, cerebral infarction, myocardial infarction and cataracts occur. Further, because immunization power is decreased by diabetes, the patients are likely to catch infections easily.
If the complications become worse, recovery is very difficult, and it is thereby important for diabetes patients to control their blood glucose level so that it will not rise above such level that no symptom is observed. For such a purpose, various antidiabetic agents, such as hypoglycemic agents, have heretofore been developed. For example, there may be mentioned, as natural materials, a hypoglycemic agent containing, as an active ingredient, tea lactone as a water-soluble polysaccharide component of tea leaves (Japanese Unexamined Patent Publication No. 4-124139), an antidiabetic agent containing, as an active ingredient, a hot water extracted fraction of banaba leaves (Japanese Unexamined Patent Publication No. 7-228539), a hypoglycemic agent of a xanthone extracted and isolated from Japanese green gentian (Japanese Unexamined Patent Publication No. 7-206673), and the like; and as chemically synthesized products, a moranolin N-substituted derivative (Japanese Examined Patent Publication No. 59-43949), a thiazolidine compound (Japanese Unexamined Patent Publication No. 4-210977) and a condensed 7-membered cyclic compound having an imidazolyl group (Japanese Unexamined Patent Publication No. 4-178381), and the like.
The chemically synthesized products generally exhibit potent effects, but give unwanted side effects, whereby long term administration gives rise to many problems. While the natural extracted products are high in safety, they typically exhibit inadequate effects.
With respect to liver dysfunction as another one of the diseases of adult people, the liver plays important rolls in vivo, for example, in detoxication, metabolism or storage of sugar, protein or lipid, and hormone control. Dysfunction of the liver often leads to fatal results for living bodies. It is well known that the causes of liver dysfunction represented by hepatitis are based on the habits of life, for example, over ingestion of alcoholic beverages, heavy drinking, heavy eating, irregular life or stress. However, it has been found that liver dysfunction is often caused by the hepatitis virus. Moreover, if viral hepatitis becomes chronic, it will often become hepatic carcinoma through liver cirrhosis, for which a suitable treatment method has been demanded.
Many proposals have heretofore been made as a treatment agent for hepatitis. However, chemically synthesized products generally exhibit potent effects, but have side effects, thereby being problematic for long term administration. Natural extracted products are high in safety, but they do not exhibit adequate effects.